Blues during thrust-off

Moin all of you!

Now that I could turn off the black-grey smoke and stink after unburnt gasoline by a new Lambda probe, I have now or even blue smokes.This is especially visible when rolling into villages, if the thrust switch is active (board calculator 0 consumption) to see in the rear view mirror! Oil consumption also by 2 L to 1000 for cross-country travel, on motorway with constant travel significantly less.What speaks for older valve shaft seals. I drive 10W 40 oil.

Question: Does anyone get control of the bluish only by changing the VSD? Otherwise he runs wonderfully, without any problems.I'm clear, the div. 4.2 Oil need, which is normal for me at 250 tkm, but he does not have to smoke in my opinion.If I then come to 1L on 1000km, am satisfied.

(P.S.: I have already tried in the search function, but I did not find a concrete answer)

MfG Marko F.